/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/

/**
 * \file pkcs5.c
 *
 * \brief PKCS#5 functions
 *
 * \author Mathias Olsson <mathias@kompetensum.com>
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
/*
 * PKCS#5 includes PBKDF2 and more
 *
 * http://tools.ietf.org/html/rfc2898 (Specification)
 * http://tools.ietf.org/html/rfc6070 (Test vectors)
 */

#include "tls/config.h"

#if defined(MBEDTLS_PKCS5_C)

#include "tls/pkcs5.h"
#include "tls/asn1.h"
#include "tls/cipher.h"
#include "tls/oid.h"

#include <string.h>

#if defined(MBEDTLS_PLATFORM_C)
#include "tls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#endif

static int pkcs5_parse_pbkdf2_params(const mbedtls_asn1_buf *params, mbedtls_asn1_buf *salt, int *iterations, int *keylen, mbedtls_md_type_t *md_type)
{
	int ret;
	mbedtls_asn1_buf prf_alg_oid;
	unsigned char *p = params->p;
	const unsigned char *end = params->p + params->len;

	if (params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
	}
	/*
	 *  PBKDF2-params ::= SEQUENCE {
	 *    salt              OCTET STRING,
	 *    iterationCount    INTEGER,
	 *    keyLength         INTEGER OPTIONAL
	 *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
	 *  }
	 *
	 */
	if ((ret = mbedtls_asn1_get_tag(&p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING)) != 0) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
	}

	salt->p = p;
	p += salt->len;

	if ((ret = mbedtls_asn1_get_int(&p, end, iterations)) != 0) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
	}

	if (p == end) {
		return (0);
	}

	if ((ret = mbedtls_asn1_get_int(&p, end, keylen)) != 0) {
		if (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
			return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
		}
	}

	if (p == end) {
		return (0);
	}

	if ((ret = mbedtls_asn1_get_alg_null(&p, end, &prf_alg_oid)) != 0) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
	}

	if (MBEDTLS_OID_CMP(MBEDTLS_OID_HMAC_SHA1, &prf_alg_oid) != 0) {
		return (MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE);
	}

	*md_type = MBEDTLS_MD_SHA1;

	if (p != end) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
	}

	return (0);
}

int mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode, const unsigned char *pwd, size_t pwdlen, const unsigned char *data, size_t datalen, unsigned char *output)
{
	int ret, iterations = 0, keylen = 0;
	unsigned char *p, *end;
	mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;
	mbedtls_asn1_buf salt;
	mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;
	unsigned char key[32], iv[32];
	size_t olen = 0;
	const mbedtls_md_info_t *md_info;
	const mbedtls_cipher_info_t *cipher_info;
	mbedtls_md_context_t md_ctx;
	mbedtls_cipher_type_t cipher_alg;
	mbedtls_cipher_context_t cipher_ctx;

	p = pbe_params->p;
	end = p + pbe_params->len;

	/*
	 *  PBES2-params ::= SEQUENCE {
	 *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
	 *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
	 *  }
	 */
	if (pbe_params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
	}

	if ((ret = mbedtls_asn1_get_alg(&p, end, &kdf_alg_oid, &kdf_alg_params)) != 0) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
	}
	// Only PBKDF2 supported at the moment
	//
	if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid) != 0) {
		return (MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE);
	}

	if ((ret = pkcs5_parse_pbkdf2_params(&kdf_alg_params, &salt, &iterations, &keylen, &md_type)) != 0) {
		return (ret);
	}

	md_info = mbedtls_md_info_from_type(md_type);
	if (md_info == NULL) {
		return (MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE);
	}

	if ((ret = mbedtls_asn1_get_alg(&p, end, &enc_scheme_oid, &enc_scheme_params)) != 0) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret);
	}

	if (mbedtls_oid_get_cipher_alg(&enc_scheme_oid, &cipher_alg) != 0) {
		return (MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE);
	}

	cipher_info = mbedtls_cipher_info_from_type(cipher_alg);
	if (cipher_info == NULL) {
		return (MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE);
	}

	/*
	 * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored
	 * since it is optional and we don't know if it was set or not
	 */
	keylen = cipher_info->key_bitlen / 8;

	if (enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING || enc_scheme_params.len != cipher_info->iv_size) {
		return (MBEDTLS_ERR_PKCS5_INVALID_FORMAT);
	}

	mbedtls_md_init(&md_ctx);
	mbedtls_cipher_init(&cipher_ctx);

	memcpy(iv, enc_scheme_params.p, enc_scheme_params.len);

	if ((ret = mbedtls_md_setup(&md_ctx, md_info, 1)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_pkcs5_pbkdf2_hmac(&md_ctx, pwd, pwdlen, salt.p, salt.len, iterations, keylen, key)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_setkey(&cipher_ctx, key, 8 * keylen, (mbedtls_operation_t)mode)) != 0) {
		goto exit;
	}

	if ((ret = mbedtls_cipher_crypt(&cipher_ctx, iv, enc_scheme_params.len, data, datalen, output, &olen)) != 0) {
		ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH;
	}

exit:
	mbedtls_md_free(&md_ctx);
	mbedtls_cipher_free(&cipher_ctx);

	return (ret);
}

int mbedtls_pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx, const unsigned char *password, size_t plen, const unsigned char *salt, size_t slen, unsigned int iteration_count, uint32_t key_length, unsigned char *output)
{
	int ret, j;
	unsigned int i;
	unsigned char md1[MBEDTLS_MD_MAX_SIZE];
	unsigned char work[MBEDTLS_MD_MAX_SIZE];
	unsigned char md_size = mbedtls_md_get_size(ctx->md_info);
	size_t use_len;
	unsigned char *out_p = output;
	unsigned char counter[4];

	memset(counter, 0, 4);
	counter[3] = 1;

	if (iteration_count > 0xFFFFFFFF) {
		return (MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA);
	}

	while (key_length) {
		// U1 ends up in work
		//
		if ((ret = mbedtls_md_hmac_starts(ctx, password, plen)) != 0) {
			return (ret);
		}

		if ((ret = mbedtls_md_hmac_update(ctx, salt, slen)) != 0) {
			return (ret);
		}

		if ((ret = mbedtls_md_hmac_update(ctx, counter, 4)) != 0) {
			return (ret);
		}

		if ((ret = mbedtls_md_hmac_finish(ctx, work)) != 0) {
			return (ret);
		}

		memcpy(md1, work, md_size);

		for (i = 1; i < iteration_count; i++) {
			// U2 ends up in md1
			//
			if ((ret = mbedtls_md_hmac_starts(ctx, password, plen)) != 0) {
				return (ret);
			}

			if ((ret = mbedtls_md_hmac_update(ctx, md1, md_size)) != 0) {
				return (ret);
			}

			if ((ret = mbedtls_md_hmac_finish(ctx, md1)) != 0) {
				return (ret);
			}
			// U1 xor U2
			//
			for (j = 0; j < md_size; j++) {
				work[j] ^= md1[j];
			}
		}

		use_len = (key_length < md_size) ? key_length : md_size;
		memcpy(out_p, work, use_len);

		key_length -= (uint32_t)use_len;
		out_p += use_len;

		for (i = 4; i > 0; i--)
			if (++counter[i - 1] != 0) {
				break;
			}
	}

	return (0);
}

#if defined(MBEDTLS_SELF_TEST)

#if !defined(MBEDTLS_SHA1_C)
int mbedtls_pkcs5_self_test(int verbose)
{
	if (verbose != 0) {
		mbedtls_printf("  PBKDF2 (SHA1): skipped\n\n");
	}

	return (0);
}
#else

#define MAX_TESTS   6

static const size_t plen[MAX_TESTS] = { 8, 8, 8, 24, 9 };

static const unsigned char password[MAX_TESTS][32] = {
	"password",
	"password",
	"password",
	"passwordPASSWORDpassword",
	"pass\0word",
};

static const size_t slen[MAX_TESTS] = { 4, 4, 4, 36, 5 };

static const unsigned char salt[MAX_TESTS][40] = {
	"salt",
	"salt",
	"salt",
	"saltSALTsaltSALTsaltSALTsaltSALTsalt",
	"sa\0lt",
};

static const uint32_t it_cnt[MAX_TESTS] = { 1, 2, 4096, 4096, 4096 };

static const uint32_t key_len[MAX_TESTS] = { 20, 20, 20, 25, 16 };

static const unsigned char result_key[MAX_TESTS][32] = {
	{
		0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,
		0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,
		0x2f, 0xe0, 0x37, 0xa6
	},
	{
		0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,
		0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,
		0xd8, 0xde, 0x89, 0x57
	},
	{
		0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,
		0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,
		0x65, 0xa4, 0x29, 0xc1
	},
	{
		0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,
		0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,
		0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,
		0x38
	},
	{
		0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,
		0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3
	},
};

int mbedtls_pkcs5_self_test(int verbose)
{
	mbedtls_md_context_t sha1_ctx;
	const mbedtls_md_info_t *info_sha1;
	int ret, i;
	unsigned char key[64];

	mbedtls_md_init(&sha1_ctx);

	info_sha1 = mbedtls_md_info_from_type(MBEDTLS_MD_SHA1);
	if (info_sha1 == NULL) {
		ret = 1;
		goto exit;
	}

	if ((ret = mbedtls_md_setup(&sha1_ctx, info_sha1, 1)) != 0) {
		ret = 1;
		goto exit;
	}

	for (i = 0; i < MAX_TESTS; i++) {
		if (verbose != 0) {
			mbedtls_printf("  PBKDF2 (SHA1) #%d: ", i);
		}

		ret = mbedtls_pkcs5_pbkdf2_hmac(&sha1_ctx, password[i], plen[i], salt[i], slen[i], it_cnt[i], key_len[i], key);
		if (ret != 0 || memcmp(result_key[i], key, key_len[i]) != 0) {
			if (verbose != 0) {
				mbedtls_printf("failed\n");
			}

			ret = 1;
			goto exit;
		}

		if (verbose != 0) {
			mbedtls_printf("passed\n");
		}
	}

	if (verbose != 0) {
		mbedtls_printf("\n");
	}

exit:
	mbedtls_md_free(&sha1_ctx);

	return (ret);
}
#endif							/* MBEDTLS_SHA1_C */

#endif							/* MBEDTLS_SELF_TEST */

#endif							/* MBEDTLS_PKCS5_C */
